| Reporter |
Alexander Shvedov (shvedov)
|
|---|---|
| Created | Apr 6, 2012 3:24:22 AM |
| Updated | Apr 6, 2012 3:26:34 AM |
| Priority | Major |
| Type | Bug |
| Fix versions | No Fix versions |
| State | Submitted |
| Assignee | Dmitry Ivanov (daivanov) |
| Subsystem | Refactoring |
| Affected versions | 7.0 Preview |
| Fixed in build | No Fixed in build |
Module Module1
Sub Main()
Dim x = 1
Dim a = New With {Key .Foo = 0}
Dim b = New With {.Boo = 0}
Foo(x)
Foo(123)
Foo(a.Foo)
Foo((a.Foo))
Foo(b.Boo)
End Sub
Sub Foo(ByRef x As Integer)
x = x + 1
End Sub
End Module
Result:
Module Module1
Sub Main()
Dim x = 1
Dim a = New With {Key .Foo = 0}
Dim b = New With {.Boo = 0}
x = Foo()
123 = Foo()
a.Foo = Foo()
(a.Foo) = Foo()
b.Boo = Foo()
End Sub
Function Foo() As Integer
Dim x As Integer
x = x + 1
Return x
End Function
End Module
VB.NET creates temporary variable when passing non-variable expressions as ByRef parameters. Correct transformation will be:
Module Module1
Sub Main()
Dim x = 1
Dim a = New With {Key .Foo = 0}
Dim b = New With {.Boo = 0}
' passing original value
x = Foo(x)
' nothing is changed, since mutation of ByRef-parameter
' are not visible outside of Foo calls for the usages below:
Foo(123)
Foo(a.Foo)
Foo((a.Foo))
' VB.NET special case for properties:
b.Boo = Foo(b.Boo)
End Sub
Function Foo(x As Integer) As Integer ' ByVal parameter
x = x + 1
Return x
End Function
End Module